So Americans not do tailored suits?

Watching this impeachment thing here, almost all of the men are wearing suits which clearly haven’t been fitted for them as that bit of the suit jacket behind the neck/shoulders rises up when they are seated.

Do US politicians not get paid well or something?

Unless, custom fitted (and still the same size) I have always worn a belt with my suit trousers. Not sure why someone would not. Once you go past your 20s hard to keep things in place at all times.